I have noticed that whenever I see documentaries with more native people, such as tribes in the Amazon, a lot of the men are either skinny, or are slightly bellied but certainly not in any way fat. Due to less food being around in the past could people not have been able to get to the same size and definition of say, Arnold Schwarznegger or Sylvester Stallone? (Terrible examples, I know) to get to look like a body builder a lot of necessary training is required which you wouldn't do, I doubt a tribesmen would start doing crunches. Would say a Roman soldier be incredibly defined and 'buff' or would it simply be undoable due to lack of large amounts of food? And the fact they didn't do 'body builder like' exercise? (Sorry if I have worded this badly.)
There's quite a lot to attaining a high amount of muscle and a low body fat, so this is a pretty long winded answer, but I hope you bear with me.
The short answer to your question is no, though.
Barring genetic oddities, it's quite impossible for a person to reach the kinds of combinations of high muscle mass and low body fat you see on high level bodybuilders today. The lack of exercise stimulus is one thing, the lack of food is another, but the key ingredient that was missing in the past is medical aid, i.e. anabolic steroids. There simply isn't a way a natural (i.e. non-user) can reach such amounts of muscle you see, for example, on Arnold during his golden years, even less so with such a low body fat.
Muscle growth in a nutshell: When you train properly and eat more than your body uses, you generate muscle tissue AND fat. When you eat less than your body needs, i.e. diet, you lose fat, but you ALSO lose some muscle. A high protein diet can mitigate this to some extent, but the lower you go in body fat, the more muscle you lose. Also, the higher the starting muscle mass is, the more likely it is to be used up by the body when it's energy deficient. Then there is also the fact that a natural trainee can only attain a certain level of muscle mass before they need to seek the aid of steroids.
Steroid use in high level bodybuilding is a public secret. Everyone in the sport knows everyone else is using, and they need to do that to keep competitive. They just can't admit it because of the stigma of cheating that's attached to it. What steroids do is allow you to go beyond your genetic potential in muscle mass and hold on to that muscle when you diet down.
All of this is not to say you would not have had strong people before. Muscle mass and power production are not even completely correlating, but that's another story. Without steroids however, a high muscle mass would require an accompanying high fat percentage, so you would not see a huge, muscle bound legionnaire with sharp six pack abs. You could see huge, strong men, but they'd also have something of a gut on them. Conversely, you could see people with low body fat, but they would be more of a wiry build.
Hope this answers your question :)
TL;DR: They didn't have anabolic steroids, so huge muscles with low body fat were not a possibility even with training and loads of food.